Well, as an ISP, I will offer the following.
The question about what works best for the last mile (your local connect) of the Internet connection is a question that has no absolute answer.
Many variables are involved. Understanding those variables will go a long way to helping you make the correct decision as to what is best for you.
When trying to decide between Cable or DSl for your service, ask the floowing questions:
1) Is the IP address a 10.x.x.x address? If yes, then avoid the ISP, if you can. Why? 10.x.x.x addresses are not routable over the Internet, which simply means the ISP is using a proxy server to handle all your Internet requests. Proxy servers are computers that do slow down as more users attach to the Internet.
2) Does the ISP require you to use PPPOE (PPP over Ethernet)? If yes, then run don't walk away from that ISP. There are many problems with using this software for Internet connections.
3) Does the ISP use DHCP for assigning IP addresses? If so, what is the lease time of the IP Address? When the lease time expires, your connection will be reset and a new IP address is assigned. This is fine for browsing the Internet as the reassignment can take aonly a few seconds, at most, but will crash any real-time program immediately.
4) Does the ISP use NAT (Network Address Translation)? This may be used in conjuction with a 10.x.x.x address. Avoid this as UDP packet problems will occur with NAT.
5) In the case of Cable: How many homes are on my node? In the case of DSL: How many users per T1 amount of traffic are on my connection? This will give you an idea of the potential bandwidth sharing issue you could have. For cable modem, they should not have more than 50 homes per node. This will give the best overall performance and reduce congestion related problems.
For DSL/T1, the ISP should not be going over 30 clients for the same reasons.
6) Does the ISP cap the bandwidth available to you? If so, what are the caps (download and upload)? This is somewhat subjective. If you do not feel the caps will impair your ability to accomplish what you want to accomplish over the Internet, then go for it.
Both types of connections have pluses and minuses and what works best for you may not work for others.
All WEB/FTP traffic for Cable users are served via caching servers on the local network for the cable ISP. This allows very fast downloads at the expense of serving stale content from time to time. This operates completely transparent to the user and cannot be avoided.
More and more DSL ISP's are using caching servers as well. So this issue is becoming moot.
ISP's are discovering that clients do not care if the content is stale, as long as it is fast.
As far as reliabilty goes, the telphone network will always be potentially more reliable than the cable network. Why? The cable network is made up on one cable carrying traffic from your ISP to you. A physical cut anywhere in that cable will bring down the entire node.
The telephone network has many different paths to your home and can switch those paths when upgrades or problems at a switch require the need to re-route. The telephone network has many redundant cable paths in the ground which facilitate this.
There is not clear answer as to which is best. The determining factors are; the ISP, the cable company or the telephone company.
A little research goes a long way.
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Roy "Skuzzy" Neese
President, AppLink Corp.
http://www.applink.netskuzzy@applink.net